Eric Anderson stars as guitar-playing Rabbi Shlomo Carlebach in the musical “Soul Doctor,” which doesn’t have much of a prayer on Broadway. Photo: Carol Rosegg

Eric Anderson stars as guitar-playing Rabbi Shlomo Carlebach in the musical “Soul Doctor,” which doesn’t have much of a prayer on Broadway. (
)

Much like its subject, the new Broadway musical “Soul Doctor” is terminally earnest and relentlessly sunny. Both also share a fish-out-of-water quality.

The show’s central character was a misfit, but he turned that quality into an asset: Shlomo Carlebach got famous when he went from studying the Torah to setting it to folky tunes in the 1960s.

Sadly, “Soul Doctor” is unlikely to be as popular as the man himself, who sang around the world until his death in 1994. While the show did well off-Broadway last summer, its hackneyed awkwardness will spell doom on the main stem.

To steer us through the singing rabbi’s journey of self-discovery — and probably make it more relatable to a gentile audience — book writer/director Daniel S. Wise uses an unlikely guide: Nina Simone.

As it turns out, the African-American jazz singer and the Jewish troubadour were friends and allies, outsiders who preached liberation. Simone (Amber Iman) turns up at regular intervals after her initial meeting with Carlebach (the upbeat Eric Anderson) in a Greenwich Village club where she’s playing piano.

This allows Iman to deliver convincing versions of Simone classics like “I Put a Spell on You” and “Sinnerman” as she checks in, Jiminy Cricket-like, on her protégé.

Carlebach was a first-generation immigrant, having fled Nazi Vienna with his family in 1938 and resettled in Brooklyn.

Young Shlomo and his brother, Eli Chaim, were groomed to succeed their scholarly father (Jamie Jackson), but strayed from that path, drawn as they were to the Hasidic movement’s exuberant brand of outreach. Shlomo, by then a rabbi, went one step further by picking up a guitar.

“Maybe dig a hole to bury it,” he says. “They have an old liturgical tradition . . . nothing new allowed.”

Carlebach is presented as a kind of holy fool, at once persistent and naive. Asked by his music producer, Milt (Michael Paternostro), if he’s heard of Peter, Paul and Mary, Carlebach replies, “I don’t know so much the New Testament.”

The show takes us up to 1972, concentrating on its star’s struggle against tradition, represented by the bigoted Reb Pinchas (Ron Orbach), and his awakening as a songwriter and spiritual leader.

This peaks with the creation of the House of Love and Prayer, a San Francisco flower-power congregation that here looks like a community-theater version of “Hair.”

Actually, that hackneyed vibe applies to the whole show, from Benoit-Swan Pouffer’s vague choreography to the groan-inducing dialogue. You often wish “Soul Doctor” had called a script doctor — especially when Shlomo’s warned that he’s “gonna do the horah/In Sodom and Gomorrah.”